R12: Activating Parallel Concurrent Processing

If you are going to R12, or have just gone to it, the article "How To Activate Parallel Concurrent Processing In R12" from My Oracle Support note ID 1525233.1 is a good overview of how to use the Parallel Concurrent Processing.  I say use, because it is on by default with R12 so it would probably be best to understand how the Generic Service Management interacts with the Internal Concurrent Manager right?